Census on giant tortoise population on Curieuse under way |21 March 2023

The second round of the Giant Aldabra Tortoise census on Curieuse will take place on Saturday

The Seychelles Parks and Gardens Authority (SPGA) Research Unit will on Saturday be conducting the second round of the Giant Aldabra Tortoise census, with the support of some thirty staff from H.Savy Insurance and Absa Bank Seychelles.

The mass census was launched in February with the aim of obtaining a near to exact figure of the tortoise population on the island, and is vital to help SPGA understand the population trend, and tortoises movement and distribution on the island.

In 1978, approximately 250 Giant Aldabra Tortoises were introduced on the island, as part of a national campaign. Initially, they were released near the Ranger’s House at Baie Laraie, but they have over the years slowly made their way across the island.

A total of 134 tortoises were identified during the last census conducted in 2019.

As for this year’s mass census, 86 free-roaming tortoises have been identified, in the Baie Laraie, Anse Papaie and Grand Anse areas. This was during the first round which took place on Saturday March 18, with the assistance of 28 participants from MCB Seychelles, including managing director Bernard Jackson.

Of the 86 who were identified, measured, weighed and tagged, the vast majority were males. 

Head of the Terrestrial Research Unit Nathalie Dusfrene explained that the population of tortoises on the island decreased in the years subsequent to introduction, since the species were heavily poached. As recently as July 2016, 23 of 28 juvenile giant tortoises were stolen from the National Park.

In recent years however, the main problem is rats.

“We do get hatchlings on the island, but some of the tortoises do not make it primarily because they are eaten by rats. We are trying to remedy the situation through a nursery, and we have a rat control programme which we introduced this year, so we hope that the population will grow.”

“We will be happy with 170 tortoises,” Ms Dusfrene stated.

The census will allow SPGA to understand where the tortoises are situated, and to try and correlate it to food sources and accessibility.

Having access to such information is also crucial to devise and implement strategies geared at successful breeding and the recovery of the population.

At present, breeding success is also affected by the fact that the male population outnumbers the female population.

Upon concluding the census, should there be a need to redistribute and bring in more female tortoises, the SPGA will gradually translocate a maximum of 50 tortoises from Fregate island, with whom they have a programme.

Participants will be tackling other areas, including Pointe Rouge during this Saturday’s activity.

A good number of the giant tortoises roaming the island which attracts a number of tourists daily were introduced between 1978 and 1982.

Hatchlings are taken care of and nurtured until they are at least five years old, before being released into the wild through the nursery, a key element of the conservation programme.

The Aldabra Giant tortoise (Aldabrachelys gigantean) is endemic to the Seychelles, and is the only species of tortoise found on the islands.

Laura Pillay